The present application is directed to a kitchen appliance with a safety interlock and, more particularly, to a safety interlock comprised of at least one portion of a drive shaft of the kitchen appliance that is movable.
Kitchen appliances commonly include a motor housing with a motor positioned therein, a bowl that is removably mountable to the motor housing and a lid that is removably mountable over a mouth of the bowl. A drive shaft extends from the motor housing into the bowl when the bowl is mounted to the motor housing. The drive shaft is rotatably driven by the motor and a processing tool is removably securable to the drive shaft for processing foodstuff within the bowl. During operation, a number of safety interlocks have been developed that prevent a user's hands from coming into contact with the processing or cutting tool when the bowl is mounted to the housing and the bowl lid is mounted to the bowl.
Prior safety interlocks may include a tab on the bowl lid that extends into a slot in the motor housing to close a switch that enables power to be provided to the motor only when the bowl and bowl lid are properly mounted. The motor housing in these side-by-side kitchen appliances extends upwardly from its base along a side of the bowl. The kitchen appliance is assembled such that a user's hand is unable to enter the processing space within the bowl when the switch is closed and the appliance is operational. The prior art side-by-side processors require the additional vertical portion of the motor housing that extends upwardly from the base of the motor housing. A tab extends from a rim of the bowl lid that extends into a slot in the side of the vertical section of the motor housing to actuate a switch within the vertical section of the motor housing. Because of this configuration, the bowl and bowl lid must be mounted in one operating position relative to the motor housing such that the tab enters the slot. The side-by-side kitchen appliance also tends to take up a relatively large amount of counter space in a kitchen.
An alternate safety interlock for a kitchen appliance may include a switch mounted in the motor housing and a movable shaft located adjacent a handle of the bowl. The movable shaft is movable between an extended and a retracted position. The bowl lid includes a tab that engages an end of the movable shaft when the bowl lid is mounted to the bowl to move the shaft to the retracted position. When the bowl is secured to the motor housing and the lid is secured to the bowl, the movable shaft is positioned in its retracted position and its end adjacent the motor housing closes the switch such that power is provided to the motor. This type of kitchen appliance is often referred to as a bowl over motor appliance or processor. In contrast to the side-by-side appliance, the bowl over motor processor generally takes up less counter space in the kitchen. However, prior bowl over motor housing kitchen appliances require the additional movable shaft located in the bowl, which complicates construction of the bowl and requires the addition of the movable shaft adjacent a periphery of the bowl or within the handle of the bowl.
The preferred embodiment of the safety interlock for a kitchen appliance in accordance with the present application includes a drive shaft with at least one portion that is movable along a drive axis between the extended and retracted positions. In the retracted position, the at least one portion of the drive shaft or drive pin in the preferred embodiment closes a switch that enables power to be provided to the motor. The drive pin is moved to the retracted position only when the bowl and lid are mounted to the motor housing in a working position. Accordingly, the safety switch is only closed when a user's hand cannot come into contact with a rotating tool within the bowl. The inclusion of the movable drive pin eliminates the complicated construction of the bowl and need for an extra shaft adjacent the handle of the bowl. In addition, the preferred kitchen appliance with the safety interlock of the present application retains the space saving advantages of the bowl over motor type kitchen appliance.